JPS5836124B2 - How to bury piles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for burying piles without noise or vibration.

Conventionally, when burying piles, the methods of burying the piles by impact with a pile driver or by applying vibrations while applying a load to sink the piles into the soil have been used, but these methods have the disadvantage of emitting vibrations and noise. However, due to pollution prevention considerations, it is currently almost impossible to use.

Therefore, it is desired to develop a method for burying piles that does not generate vibrations or noise. For example, while drilling a hole using an earth auger screw, bentonite milk is injected to protect the hole wall, and cement for foot hardening is added when the hole is completed. Method of pouring mortar, removing screws, and inserting piles (Japanese Patent Laid-open No. 4
9-34769), an improved method is to use a casing to prevent the hole wall from collapsing during drilling (Japanese Patent Publication No. 4939045), or to first drill a large diameter hole and fill the hole with fill cement. After filling and curing properly, re-drill the hole with a diameter slightly larger than the diameter of the pile (
Special Publication No. 48-14085) etc. have been proposed.

The first method was not sufficiently effective, as is clear from the fact that an improved method was immediately proposed by the same inventor, and the second method was based on the use of a casing and a bentonite solution mixed with cement during drilling. In addition, the third method has the disadvantage that it requires the formation of fill cement and the drilling of holes twice.

Apart from this, there is also a hollow construction method in which an earth auger screw is inserted into a ready-made pile that has a hollow part with an open end, and the pile is buried together while rotating the screw, but in both of the above methods, the auger screw is In order to use the soil, it is necessary to treat the excavated soil that is generated and discharged to the ground surface by drilling the hole, and a large amount of muddy water such as bentonite liquid that is injected to prevent the collapse of the hole wall floods the work site due to the insertion of piles. This poses a major problem both economically, as it requires a large amount of money, and also in terms of work efficiency and safety due to poor scaffolding.

The present inventor has been engaged in pile burying work for many years, and as a result of closely observing and studying the process, he has discovered that it is possible to bury piles without using an auger screw, and has completed the present invention.

That is, the gist of the present invention is to drill a hole using a drilling drill having a regular polygonal cross section, and instead of substantially discharging the excavated soil onto the ground surface, the rotation of the drilling drill tightly compresses the excavated soil against the hole wall. The method for burying piles is to prevent the collapse of the pile, and to prevent the pile from collapsing.

The present invention will be specifically described below.

As mentioned above, the present invention is the result of many years of experience and numerous studies.
It does not require the excavation of excavated soil on the ground surface, does not require the use of bentonite liquid, etc. to prevent collapse, and can use ready-made piles with closed ends, making it economically inexpensive, extremely easy to build, and strong. We have developed a construction method that can provide sufficient bearing capacity.

FIG. 1 is a front view of an example of a drilling drill 1 used in the method of the present invention, and FIG. 2 is a sectional view taken along line AA' in FIG. 1.

As can be easily understood from both figures, the drilling cone 1 has a regular polygonal pyramid shape at the bottom and a regular polygonal prism shape at the top.

Here, polygon means more than a triangle, and usually ranges from triangular to hexagonal, with square being the most convenient.

It is easy to drill a triangular hole, but the density of the excavated soil on the hole wall is weak, and depending on the soil type, it may not be possible to sufficiently avoid the risk of the hole wall collapsing. Although the compaction effect is strong, the load required for drilling is large.

Normally, a square pyramid provides a sufficient compaction effect, and the load required for drilling does not become excessive.

As is clear from Figure 1, the regular polygon referred to here is a general shape, and the sides connecting the angles, that is, the faces of the cone, do not have to be straight lines, but rather the sides are concave toward the center of the axis. It is preferable to have a curved shape.

By forming the sides into a curved shape concave toward the axial center, the load required for rotation of the drill bit can be reduced.

Therefore, in the case of a triangle, it is sufficient to have straight sides, and in the case of a pentagonal or hexagonal shape, it is clearly preferable that the sides be curved as described above.

It is preferable that the diameter of rotation around the axis of the awl is slightly larger than the diameter of the pile to be buried.

As mentioned above, the upper part of the cone is prismatic.

This prismatic section functions to compress the excavated soil against the hole wall.

But? It is not necessary that the entire length of the cone be prismatic, but it is sufficient to have a length sufficient to tightly press the hole wall and sufficiently fix the cone, and the upper part thereof may be a rotating shaft with a small diameter.

Whether the entire length should be prismatic or part of it should be a rotating shaft with a small diameter depends on the force required to rotate the drill, the soil quality, and the depth of the hole being drilled, so it cannot be determined unconditionally, but it is suitable for drilling holes of normal depth. It is preferable that substantially the entire length is prismatic.

In the above description, the lower part of the cone is shaped like a polygonal pyramid, but a conventionally known excavation head can also be used for this part.

A through hole is provided in the center of the drill bit to introduce air or water from the top to the tip of the drill bit.

3 to 8 are sectional views for explaining the method of the present invention, and the awl 1 and the stake 4 are not sectional views but front views.

From FIG. 3 to FIG. 8, the steps are shown in the order of progress.

As shown in Fig. 3, first, a drilling drill bit 1 with a diameter slightly larger than the diameter of the pile 4 to be buried is connected to an earth auger motor, and is drilled into the ground while rotating at the position of the pile core to be buried. Eventually, the drill bit can be easily drilled into the ground.

In this case, the excavated soil is not carried upwards, but is pushed sideways and tightly compressed against the hole wall, strengthening the hole wall.

During excavation, depending on the soil quality, it is possible to reduce the friction between the drill bit and the soil by supplying an appropriate amount of compressed air or a small amount of water using the through hole 2 provided in the center of the drill bit, but this is not the case with conventional methods. However, these deliveries are not a mandatory requirement.

Furthermore, even if water is to be supplied, it is only necessary to supply a small amount of water, which is sufficient to reduce friction, so that water will not overflow and impair the foothold on the ground surface.

As shown in Fig. 4, when the drilling drill bit 1 reaches the target support layer, the drilling drill bit 1 is kept in that position for a while and rotated to complete the tight pressure on the hole wall, and during or after that, as shown in Fig. 5. It is preferable to inject cement milk 3 for hardening the drilled hole from the tip of the drill hole using the through hole 2 provided at the center of the drill hole, for example, as shown by the arrow.

Injection of cement milk 3 for hardening is not an essential requirement, but it is required in most cases in recent construction work.

In addition, since a large supporting force can be obtained, the number of piles can be reduced for the same load capacity, so it is recommended to use this method.

Thereafter, as shown in FIG. 6, the drilling drill is gradually pulled up to complete the drilling.

Next, the pile 4 is inserted into the drilled hole as shown in FIG. 7, and the pile 4 is lowered to the bottom of the drilled hole by its own weight as shown in FIG. 8.

When the pile reaches the bottom of the drilled hole, a portion of the cement milk previously injected is pushed away by the pile and pushed up, bonding to the pile over a wide area and strengthening the fixation of the pile 4.

Although the shape of the pile to be buried in the method of the present invention is not particularly limited, it is preferable to use a ready-made pile with a closed end.

Compared to hollow piles, piles with closed tips not only have a larger bearing capacity at the tip, but also have a larger amount of cement milk pushed up when the pile is inserted, making them stronger as they are fixed with cement over virtually the entire length of the pile. Supporting capacity can be obtained.

The ability to use piles with closed ends is one of the advantages of the method of the present invention compared to the medium excavation method or the method of Japanese Patent Publication No. 49-39045.

[Brief explanation of the drawing]

FIG. 1 is a front view of an example of a drilling drill used in the present invention, FIG. 2 is a sectional view taken along line A-A' in FIG. 1, and FIGS. 3 to 8 are diagrams for explaining the method of the present invention. A cross-sectional view,
The steps are shown in order of progression. 1...Drilling L2...Through hole, 3...
...Cement milk, 4...Spinning

Claims (1)

[Scope of Claims] 1. A drilling drill having a drilling head at the lower end and a regular polygonal prism shape at the upper end is rotated and lowered, and while drilling, the excavated soil is tightly compressed against the inner circumferential wall of the hole, thereby drilling a hole to a predetermined depth. A method for burying piles, which comprises: completing the process, then pulling up the drilling drill, and then inserting and burying the piles into the drilled hole. 2. The method for burying a pile according to claim 1, wherein the excavation drill is a regular square prism instead of a regular polygonal prism, and each face is concave. 3 The length of the drilling drill is the same as or a fraction of the total length of the drilling depth.
A method for burying a pile according to claim 1, wherein the pile has a length of .